Agricultural fertilizer is used to help farmers keep their plants and crops healthy. Fertilizer is necessary because crops that are cut down do not die and decay like plants in the wild. In nature, the decaying plants enrich the soil and replenish the minerals and nutrients that the crops extracted from it. Scientists have found that plants need 13 different nutrients to grow. Some of these are nitrogen, phosphorus, potassium, sulfur, calcium, and boron. The three nutrients that are used up by plants in the soil are nitrogen, phosphorus, and potassium. For this reason, agricultural fertilizer almost always contains these three ingredients as well as others.
Fertilizers have been used for many years, but chemical inorganic ones began to be used during the industrial revolution. Inorganic varieties are synthetics that are manufactured. It is thought that about half of the world’s population eats food that was grown with synthetic nitrogen fertilizer, so it is extremely important to world food production. Organic fertilizers are gaining in popularity due to the demand for organic foods of all types. This type is also a green product that is more environmentally friendly than inorganic products. Organic varieties originate from plant or animal sources that are natural. An example of an organic fertilizer is cow manure.
Organic fertilizer is often preferred because it improves the life of the soil. It also improves the long-term productivity of the soil with its natural mineral deposits. Besides manure, organic fertilizer also originates from compost, seaweed, worm castings, and guano. These natural materials must be properly composted or they may have disease causing bacteria that could cause sickness in those who eat food grown in soil that was treated with this material.
Agricultural fertilizer can be in a granular form, liquid, or long-lasting granular forms. The granular form is the most common, and it is spread by farmers with a fertilizer spreader. Liquids have the advantage of being absorbed instantly, so they are used when the need for fertilizer is an immediate need. Long-lasting forms slowly release nutrients back into the soil over a period of weeks of months. Farmers must use the correct amount of this substance, regardless of the type that they use. Using too much is known as over-fertilization, and it results in fertilizer burn. When the burn occurs, the roots of the plant become too dry. In some cases, the plants may even die from too much of this substance.
Farmers often test the soil and plant tissue to determine whether or not the soil needs fertilizer. For soil testing, farmers may do soil sampling, a process in which samples of soil are taken from different areas of the farm land or garden. The soil is then tested in a lab to determine whether the chemical levels are appropriate for a new crop planting or if agricultural fertilizer needs to be added. It is important to know which chemicals are deficient so that the soil is in its optimum condition for plant growth. People who have been farming for years can often look at their plants and know if the soil needs fertilizer. A study of the plant tissue in the lab is more accurate in determining exactly which nutrients are sufficient and which are deficient. Testing will show which nutrients are in the plant tissue and which ones are missing. Low-level nutrients can then be replaced with fertilizer.
Agricultural fertilizers must be used with extreme caution. This is because they not only affect the soil on the farm where they are used, but they also affect the nearby water sources, wildlife, air quality, and crops on nearby farms. Fertilizer run-off is a major problem in depleting oxygen in the ocean as well, so it must be used with extreme caution.